Class 12 · Mathematics (041)
Unit 10 · Class 12Mathematics (041)
Vectors and Three-Dimensional Geometry

Vectors

Vector algebra: addition, scalar and cross products, projections.

Lessons
4 concepts
  1. 1
    Vector Basics
    Magnitude ∣a⃗∣|\vec a|, unit vector a^=a⃗/∣a⃗∣\hat a = \vec a / |\vec a|.
  2. 2
    Dot Product
    a⃗⋅b⃗=∣a⃗∣∣b⃗∣cos⁡θ\vec a \cdot \vec b = |\vec a||\vec b|\cos\theta; used to find angle and projection.
  3. 3
    Cross Product
    ∣a⃗×b⃗∣=∣a⃗∣∣b⃗∣sin⁡θ|\vec a \times \vec b| = |\vec a||\vec b|\sin\theta; direction given by right-hand rule.
  4. 4
    Applications
    Area of parallelogram =∣a⃗×b⃗∣= |\vec a \times \vec b|; area of triangle =12∣a⃗×b⃗∣= \tfrac{1}{2}|\vec a \times \vec b|.
Skills to practise
Practice bank for this unit is in progress. You can still read the lessons above.
Gyaan Maths — CBSE Class 6-12, built for board-toppers.
v1.1 · Sept 2026